Irritant Contact Dermatitis (ICD): The Most Common Skin Irritation from Wearables

ICD skin irritation may causes a burning sensation

Contact dermatitis is skin irritation that occurs from something that directly contacting the skin. There are two main types of contact dermatitis. (1) Allergic Contact Dermatitis (ACD) (2) Irritant contact Dermatitis (ICD).

ACD is rare, ICD is common.

ICD is the most common type of skin irritation that occurs on skin under wearable devices like smart watches and rings.

ACD damages the skin when your adaptive immune system mistakenly thinks that a chemical absorbed by the skin is a something dangerous (like an infection) and attacks the skin cells that present that chemical.

ICD is caused when something in physical contact with the skin causes direct damage to skin cells. For example, if something like acid is spilled on the skin, it physically damages the skin and creates an injury. An acid injury, also known as a chemical burn, is a subtype of ICD.

The ICD process of skin injury starts from the outermost layers of the skin cells and then works its way toward the inner layers of skin. How fast an ICD develops and how severe an ICD injury becomes depends on several factors including (1) how much damage the irritant does to the skin (adjuvanticity) (2) the concentration of the irritant and (3) how long the irritant is in contact with the skin. Common irritants that accumulate in the microenvironment between the device and skin include:

• moisture

• heat

• soaps

• skin products applied by the user

Mild ICD only affects the outermost layers of skin (top layer of the epidermis) and may only causes white scaling and mild itching.

Moderate ICD extends deeper into the epidermis and triggers inflammation by activation of the innate immune system. When inflammation occurs, there will be redness, swelling and symptoms like itching, stinging or a burning sensation. Because the skin damage goes deeper into the epidermis, the scale is thicker.

Severe ICD extends even deeper into the epidermis and triggers even greater inflammation. Enough inflammation can occur where thin-walled blisters may develop. Stinging and burning sensations are more intense. Some individuals might interpret the appearance and symptoms of a severe ICD reaction to be a thermal burn injury.

Some clues that might make you suspect ICD over ACD:

• has a shellac type scale or burn-like appearance

• occurs sporadically instead of with each use of the device

• soaps easily access the microenvironment between the device and skin--for instance, the user wears the device while showering

• moisture accumulating in the microenvironment between the device and skin seems to be a trigger (seems to occur after excercise)

• burning and stinging sensations are greater than an itching sensation

There are different ways to reduce the likelihood ICD from occurring with wearable devices. Many of the strategies have to do with how the device is design, the choice of the materials used and the instructions given to the user about best practices for using and cleaning the device.

BOHLD has worked with clients on each of these aspects and is experienced in (1) evaluating prototype designs and providing solutions to minimize ICD (2) familiar with functional material properties and can recommend specific material classes to minimize ICD and (3) has written best practice care and device fit instructions for several skin worn devices.

Contact BOHLD